I am trying to understand the process of switching out my HDD for an SSD and then replacing my optical drive with the same HDD just removed in a late 2011 Macbook Pro 15.4".

Is there any benefit to doing this vs. just replacing the optical drive with a new SSD and leaving the HDD where it is at?

My main intent in adding a SSD is to increase the speed of my computer and not necessarily adding more space. My HDD is 750GB and I'm not even close to filing it up. I do have programs on my HDD like Microsoft Office that I don't want to lose and don't have the means of reinstalling.

Any suggestions would be great and a detailed description of how to go about this would also be greatly appreciated.

I've never used these OWC optical drive replacement kits but haven't ever heard anything negative about them; the power draw from the SSD is so much less than a traditional spinning HDD that I doubt you'll notice much difference in battery life.

Swapping the HDD out is trivial; replacing the optical with any other drive will be a bit more complicated, but do-able.

If you decide to only upgrade the HDD to SSD and retain your optical drive, you could use any external 2.5" SATA to USB enclosure to clone from the HDD to the SSD; I've done this plenty of times.

In any case, upgrading to a SSD is a really great performance improvement, especially on an older portable.

Thanks for the response. You mentioned that I can use a SATA to USB enclosure to clone the HDD to SSD, does that include programs. In other words would I be able to transfer my microsoft office program (not just files) from my HDD to SSD without reinstalling?
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user37884Jan 4 '13 at 18:35

Yes; in this context 'cloning' means copying the entire drive - OS/system, applications, data - from one volume to another. The utility I linked to, Carbon Copy Cloner, is the standard for Macs for cloning systems (even while booted). If you used that, your new SSD would have the exact same OS, apps, and data (just be tremendously faster).
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da4Jan 4 '13 at 18:40